This invention relates to an actuating mechanism for a drum-in-hat parking brake associated with a disc brake rotor for a heavy truck disc brake assembly.
The large axle tube on a heavy truck takes up so much space inside the hat of a disc brake that before my invention it was not feasible to incorporate a drum-in-hat parking brake in the hat of the disc brake rotor. Formerly, either the parking brake was placed on the drive shaft of the truck behind the transmission, or the hydraulically operated caliper of the disc brake was provided with mechanically operated means whereby the caliper could also serve as the parking brake. The latter arrangement is shown in my earlier U.S. Pat. No. 3,934,684, issued Jan. 27, 1976.